The invention relates in general to the testing of fuel injectors and in particular to a method and apparatus for aligning and inserting a fuel injector in a test head.
Automatic testing machinery for fuel injectors utilize a moving conveyor on which are carried pucks. Each puck carries a fuel injector. The pucks are routed to various testing stations to assure that the newly manufactured fuel injector meets quality standards.
A puck with an injector carried therein is automatically placed under a test head. An actuator such as a hydraulic or pneumatic cylinder is located beneath the puck at its position beneath the test head. A fixed cone is mounted on the actuator for engaging the bottom of the puck. The fixed cone raises the puck upwards toward the test head so that the injector is inserted in the test head. An O-ring on the end of the injector provides a seal inside the test head. If the injector is not properly aligned with the test head, false leak readings may result. That is, the leakage may be occurring where the O-ring seals with the test head rather than in the injector itself. If that occurs, a perfectly good injector may be rejected because of a false leak reading.
Because of the speed at which the actuator raises the puck, the puck may not have enough time to center itself on the fixed cone before the injector engages the test head. The result is misalignment of the injector in the test head and/or damage to the top O-ring. At the last test head, the injector is fully manufactured and all other tests have been conducted. Therefore, to reject a good injector at the last test head is to lose all the parts and labor invested in a completely manufactured injector. If the rejection of good injectors at the last test head can be reduced, substantial savings can be realized.